The Internet of Vehicles can provide, to a vehicle, entertainment service information, service information such as efficiency, and security information that can protect the vehicle from a collision, where the security information is related to driving information of the vehicle. Generally, a driving speed of a vehicle is relatively fast. To avoid a collision, a transmission delay of the security information is required to be within 100 ms. Coverage of a cellular network is wide, a process of establishing a link is relatively complex, and it is hard to ensure a time latency. Therefore, a vehicle direct communication technology, for example, a dedicated short range communications (DSRC) technology, may be used for communication to send a security message within a relatively short distance with a relatively long delay. In some cases, the security message also needs to be transmitted within a long distance. For example, when a vehicle collision occurs at a key road section, the security message may need to be notified to a vehicle that is far away.
In the prior art, a vehicle terminal may send a security message by using a DSRC device. A vehicle terminal receiving the security message continues forwarding the security message. A requirement on a long-distance coverage of the security message is satisfied after multiple times of forwarding by vehicles. However, because a sending distance of the DSRC device is 300 m, the security message can be forwarded only when there are at least two vehicles within a range of 300 m. However, in a case in which vehicle intensity is excessively high, if each vehicle forwards the security message after receiving the security message, a broadcast storm will occur. As a result, the security message cannot be forwarded to a vehicle within a predetermined distance range within a specific time.